A large proportion of the world's population does not have access to a consistent and reliable supply of mains electricity. Underdeveloped countries or regions remote from populated areas frequently suffer from rationing of electrical power, often implemented by means of “load shedding,” that is, the creation of intentional power outages or failures of the electrical power distribution network.
The storage of vaccines, food items, and beverages at appropriate temperatures is difficult in such areas where this absence of a constant and/or reliable supply of electrical power restricts the widespread use of conventional refrigeration equipment. Vaccines, for example, are required to be stored within a narrow temperature range between approximately 2° C. and 8° C., outside of which their viability can be compromised or destroyed. Similar problems arise in connection with the storage of food, particularly perishable food items, and packaged beverages such as canned or bottled drinks.